How are extratropical cyclones formed?

In our senior high school geography study, it involves a wide range, but when studying and reviewing, we can link all the parts of knowledge, so that geography knowledge will not be so confusing. Below, I collected and sorted out "How is the extratropical cyclone formed?" ",let's start thinking from this part of knowledge.

The extratropical cyclone, also known as "extratropical depression" or "frontal cyclone", appears in the middle and high latitudes, and the central pressure is lower than the surrounding area, which is an approximately elliptical air vortex. The extratropical cyclone is one of the important weather systems that affect large-scale weather changes, with an average diameter of 1000 km, ranging from several hundred km to over 3,000 km.

The extratropical cyclone occurs at the intersection of polar cold air and tropical warm air, and has a frontal structure. The structural model of a mature extratropical cyclone is: the central pressure is the lowest, the warm front extends forward from the center, the cold front extends backward, there is warm air between the cold and warm fronts, and there is cold air north of the cold and warm fronts. The warm air on the front rises spirally, and the cold air under the front expands and sinks in a fan shape. The whole life history of extratropical cyclones from generation, development to extinction is generally 2? Six days. On the same front, 2? Five temperate cyclones advance from west to east in turn, which is called "cyclone family".

Temperate cyclones have an important influence on the weather changes in middle and high latitudes. The corresponding weather model is: there is a wide warm front cloud system and continuous precipitation weather in front of the cyclone; Behind the cyclone is a relatively narrow cold front cloud system and precipitation weather; The central part of the cyclone is a warm air mass. If the water vapor in the heating mass is sufficient and unstable, stratocumulus and stratocumulus may appear, and it will rain in Mao Mao. If the air mass is dry, only some thin clouds can be produced without precipitation.

Cyclone is a weather system that produces large-scale precipitation, strong wind and other weather phenomena, accompanied by heavy rain or strong convective weather, and sometimes the maximum wind force near the ground can reach more than 10. It is not only determined by the temperature and pressure field structure of cyclone, but also related to air stability, water vapor conditions, topography and its development stage. It is an important weather system in temperate regions.

The above content is "How is the extratropical cyclone formed?" I believe that after you have mastered this part of knowledge, our knowledge reserve will be more perfect, thus helping us solve more geographical problems.